Giants pitcher Matt Cain exits game vs. Rockies with strained right hamstring

Matt Cain pitched the Giants' first perfect game in franchise history in June 2012. (Thearon W. Henderson/Getty Images)

Giants pitcher Matt Cain exited vs. the Colorado Rockies in the fourth inning on Wednesday night and has been diagnosed with a strained right hamstring, according to tweets from Andrew Baggarly of CSN Bay Area that cited information from the team.

The injury appeared to happen after the Giants' three-time All-Star caught Charlie Blackmon looking to end the third inning, but he showed some discomfort after he left the mound. In his place, Yusemiero Petit started the fourth inning.

In his three innings pitched, the right hander didn't allow a hit or a walk and had struck out three batters.

SI WIRE:  White Sox closer Matt Lindstrom to have ankle surgery Friday, out three months